Right now, there aren't rear seat airbags. In fact, other than seatbelts, there's no real protection for frontal collisions (as there are several models with side curtain airbags that protect the rear passengers as well as those in the front). [TRW photo]

Safety in the Rear Seat

Not to put too fine a point on it, you've got seatbelts in the back. End of story. For now.

According to the National Center for Health Statistics (cdc.gov), when it comes to the 10 leading causes of injury deaths, motor vehicles are a major cause particularly for young people—no, not necessarily young people who are behind the wheel, either. For 2010, the latest statistics, for those aged 1-4, “Unintentional MV Traffic” was the second-leading cause of death. For ages 5-9, 10-14, and 15-24, it was the leading cause of death. These are not all deaths in the car. But presumably a majority.

Steven J. Peterson, director of Engineering, TRW Automotive Occupant Safety Systems, North American Region, Global Systems (trw.com), points out that children under 12 are generally passengers in rear seats. Children. Young adults. The very elderly. These are the typical rear-seat passengers. And the first and the last tend to be among the most fragile.

Safety for the driver and front seat passenger has been an area of considerable concern for the past several years. Technologies from advanced airbags to systems that monitor the driver’s steering wheel inputs are all being deployed.

But what is the safety technology that is part of a passenger car’s second row? A seatbelt. While there are child safety seats and booster seats, according to the Center for Disease Control and Prevention, “Child restraint systems are often used incorrectly. One study found that 72% of nearly 3,500 observed car and booster seats were misused in a way that could be expected to increase a child’s risk of injury during a crash.” And let’s not overlook the fact that it isn’t just children who sit back there. What’s more, seatbelt use is far from being universal in front seats, and things are less connected in the back. According to the Governors Highway Safety Association (ghsa.org), 16 states have secondary seatbelt laws. This means drivers cannot be pulled over for non-seatbelt use only. But even in states where there are primary laws, there is not full belt-wearing compliance.

According to the CDC, seatbelt use is 88% in states with primary laws; 79% in states with secondary laws, which means that there are plenty of unbelted people. And generally, the laws apply to front seats (e.g., in Michigan, where this is being written, the law is primary and covers only front seats; in Ohio, where this is being published, the law is secondary and covers all seats for those from 8 to 14 and only the front seat for those 15 or older).

As Peterson points out, the seatbelts in the rear seats of cars are not what they are in the front. The seatbelts back there don’t offer pretensioning. No load limiting. No real energy management. Which brings us back to children and the elderly. “You want the seatbelt to perform differently for large and small occupants,” Peterson says. So for kids, the issue is primarily one of protecting their heads, which are proportionately large. For older people, it is about not having excessive chest loads, which can be proportionately brittle.

Airbags? Well, as Peterson points out, while there is no technological inhibitor, there is an issue of packaging, especially given that while most front seats in cars are in known positions with known occupants (or an empty passenger seat), in the rear, “You don’t know what’s back there—a child, an old person, someone belted, someone unbelted, a dog . . .” Sensors would certainly be necessary.

But the challenge is one of demand and legislation. The latter doesn’t really exist compared to the front seat (which explains why there are airbags in the front of the car). And so far, the demand from the public hasn’t been that great for improvements in rear seat safety, although Peterson says this is likely to change because Euro NCAP is going to start including a 5th percentile female dummy in the rear seat during full-width frontal tests, and Q6 and Q10 children are planned for 2016. Which means that the “star” ratings are going to be calculated with the results of the rear seat safety performance included. Those companies that have “five-star” ratings will no doubt promote that in their advertising, so other OEMs will have to catch up.

Peterson says that initially, basic pretensioning and load limiting belts are going to be deployed in Europe to meet the 2015 assessments. Presumably, the technology will get more extensive as people recognize the importance of rear seat safety, and as the assessment regimes are enhanced.

In the U.S., it will probably require the Insurance Institute for Highway Safety and NCAP scores to drive the tech into cars. Or maybe when aged Baby Boomers start getting relegated to the rear seat, they may demand additional safety.